图片说明](https://img-ask.csdn.net/upload/201502/18/1424249621_652792.png)
还有一张传不上去
这都是些什么问题?麻烦大致讲下 谢谢
代码如下
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class Test extends JFrame implements ActionListener{
JLabel lbl1,lbl2;
JTextField txt1,txt2,txtResult;
JButton btnCalc;
public Test(){
super("我的第一个Swing程序");
txt1=new JTextField(5);
lbl1=new JLabel("=");
txtResult=new JTextField(7);
txtResult.setEditable(false);
btnCalc=new JButton("计算");
btnCalc.addActionListener(this);
Container c=getContentPane();
c.setLayout(new FlowLayout());
c.add(txt1);
c.add(lbl1);
c.add(txt2);
c.add(lbl2);
c.add(txtResult);
c.add(btnCalc);
setSize(500,100);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent e){
float num1=0,num2=0,result=0;
try{
num1=Float.parseFloat(txt1.getText());
num2=Float.parseFloat(txt2.getText());
result=num1+num2;
}catch(Exception ex){
txtResult.setText("数据非法!");
return;
}
txtResult.setText(Float.valueOf(result).toString());
}
public static void main(String[] args){
new Test();
}
}